【最佳实践】Docker Scan扫描镜像漏洞-云原生生态圈

Docker scan本地扫描镜像漏洞

2020年年底，Docker hub推出镜像自动扫描的功能，同时Docker也支持了在本地通过Docker命令选项的方式支持镜像漏洞扫描，目前Docker Desktop for Mac以及window上的Docker都可以通过Docker scan子命令扫描本地镜像是否存在漏洞软件。

Docker Desktop For Mac

使用docker scan的时候需要登录Docker Hub的账号，同时docker scan支持一些不同的选项

Options:
      --accept-license    接受使用第三方扫描提供商
      --dependency-tree   显示带有扫描结果的依赖树
      --exclude-base      从漏洞扫描中排除基础镜像 (requires --file)
  -f, --file string       与image关联的Dockerfile，提供更详细的结果
      --group-issues      聚合重复的漏洞并将其分组为1个漏洞 (requires --json)
      --json              以json格式输出结果
      --login             使用可选令牌(带有--token)向扫描提供程序进行身份验证，如果为空则使用web base令牌
      --reject-license    拒绝使用第三方扫描提供商
      --severity string   只报告提供级别或更高的漏洞(low|medium|high)
      --token string      登录到第三方扫描提供程序的认证令牌
      --version           显示扫描插件版本

指定Dockerfile

$ docker scan -f Dockerfile docker-scan:e2e
Testing docker-scan:e2e
...
✗ High severity vulnerability found in perl
  Description: Integer Overflow or Wraparound
  Info: https://snyk.io/vuln/SNYK-DEBIAN10-PERL-570802
  Introduced through: git@1:2.20.1-2+deb10u3, meta-common-packages@meta
  From: git@1:2.20.1-2+deb10u3 > perl@5.28.1-6
  From: git@1:2.20.1-2+deb10u3 > liberror-perl@0.17027-2 > perl@5.28.1-6
  From: git@1:2.20.1-2+deb10u3 > perl@5.28.1-6 > perl/perl-modules-5.28@5.28.1-6
  and 3 more...
  Introduced by your base image (golang:1.14.6)



Organization:      docker-desktop-test
Package manager:   deb
Target file:       Dockerfile
Project name:      docker-image|99138c65ebc7
Docker image:      99138c65ebc7
Base image:        golang:1.14.6
Licenses:          enabled

Tested 200 dependencies for known issues, found 157 issues.

According to our scan, you are currently using the most secure version of the selected base image

不扫描该镜像的基础镜像

$ docker scan -f Dockerfile --exclude-base docker-scan:e2e
Testing docker-scan:e2e
...
✗ Medium severity vulnerability found in libidn2/libidn2-0
  Description: Improper Input Validation
  Info: https://snyk.io/vuln/SNYK-DEBIAN10-LIBIDN2-474100
  Introduced through: iputils/iputils-ping@3:20180629-2+deb10u1, wget@1.20.1-1.1, curl@7.64.0-4+deb10u1, git@1:2.20.1-2+deb10u3
  From: iputils/iputils-ping@3:20180629-2+deb10u1 > libidn2/libidn2-0@2.0.5-1+deb10u1
  From: wget@1.20.1-1.1 > libidn2/libidn2-0@2.0.5-1+deb10u1
  From: curl@7.64.0-4+deb10u1 > curl/libcurl4@7.64.0-4+deb10u1 > libidn2/libidn2-0@2.0.5-1+deb10u1
  and 3 more...
  Introduced in your Dockerfile by 'RUN apk add -U --no-cache wget tar'



Organization:      docker-desktop-test
Package manager:   deb
Target file:       Dockerfile
Project name:      docker-image|99138c65ebc7
Docker image:      99138c65ebc7
Base image:        golang:1.14.6
Licenses:          enabled

Tested 200 dependencies for known issues, found 16 issues.

以json格式输出扫描结果

JSON格式显示镜像扫描结果

聚合分组显示扫描信息

$ docker scan --json --group-issues docker-scan:e2e
{
    {
      "title": "Improper Check for Dropped Privileges",
      ...
      "packageName": "bash",
      "language": "linux",
      "packageManager": "debian:10",
      "description": "## Overview\nAn issue was discovered in disable_priv_mode in shell.c in GNU Bash through 5.0 patch 11. By default, if Bash is run with its effective UID not equal to its real UID, it will drop privileges by setting its effective UID to its real UID. However, it does so incorrectly. On Linux and other systems that support \"saved UID\" functionality, the saved UID is not dropped. An attacker with command execution in the shell can use \"enable -f\" for runtime loading of a new builtin, which can be a shared object that calls setuid() and therefore regains privileges. However, binaries running with an effective UID of 0 are unaffected.\n\n## References\n- [CONFIRM](https://security.netapp.com/advisory/ntap-20200430-0003/)\n- [Debian Security Tracker](https://security-tracker.debian.org/tracker/CVE-2019-18276)\n- [GitHub Commit](https://github.com/bminor/bash/commit/951bdaad7a18cc0dc1036bba86b18b90874d39ff)\n- [MISC](http://packetstormsecurity.com/files/155498/Bash-5.0-Patch-11-Privilege-Escalation.html)\n- [MISC](https://www.youtube.com/watch?v=-wGtxJ8opa8)\n- [Ubuntu CVE Tracker](http://people.ubuntu.com/~ubuntu-security/cve/CVE-2019-18276)\n",
      "identifiers": {
        "ALTERNATIVE": [],
        "CVE": [
          "CVE-2019-18276"
        ],
        "CWE": [
          "CWE-273"
        ]
      },
      "severity": "low",
      "severityWithCritical": "low",
      "cvssScore": 7.8,
      "CVSSv3": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:F",
      ...
      "from": [
        "docker-image|docker-scan@e2e",
        "bash@5.0-4"
      ],
      "upgradePath": [],
      "isUpgradable": false,
      "isPatchable": false,
      "name": "bash",
      "version": "5.0-4"
    },
    ...
    "summary": "880 vulnerable dependency paths",
      "filesystemPolicy": false,
      "filtered": {
        "ignore": [],
        "patch": []
      },
      "uniqueCount": 158,
      "projectName": "docker-image|docker-scan",
      "platform": "linux/amd64",
      "path": "docker-scan:e2e"
}

显示指定级别的漏洞，只有高于此级别的漏洞才会显示出来

$ docker scan --severity=medium docker-scan:e2e
./bin/docker-scan_darwin_amd64 scan --severity=medium docker-scan:e2e

Testing docker-scan:e2e...

✗ Medium severity vulnerability found in sqlite3/libsqlite3-0
 Description: Divide By Zero
 Info: https://snyk.io/vuln/SNYK-DEBIAN10-SQLITE3-466337
 Introduced through: gnupg2/gnupg@2.2.12-1+deb10u1, subversion@1.10.4-1+deb10u1, mercurial@4.8.2-1+deb10u1
 From: gnupg2/gnupg@2.2.12-1+deb10u1 > gnupg2/gpg@2.2.12-1+deb10u1 > sqlite3/libsqlite3-0@3.27.2-3
 From: subversion@1.10.4-1+deb10u1 > subversion/libsvn1@1.10.4-1+deb10u1 > sqlite3/libsqlite3-0@3.27.2-3
 From: mercurial@4.8.2-1+deb10u1 > python-defaults/python@2.7.16-1 > python2.7@2.7.16-2+deb10u1 > python2.7/libpython2.7-stdlib@2.7.16-2+deb10u1 > sqlite3/libsqlite3-0@3.27.2-3

✗ Medium severity vulnerability found in sqlite3/libsqlite3-0
 Description: Uncontrolled Recursion
...
✗ High severity vulnerability found in binutils/binutils-common
 Description: Missing Release of Resource after Effective Lifetime
 Info: https://snyk.io/vuln/SNYK-DEBIAN10-BINUTILS-403318
 Introduced through: gcc-defaults/g++@4:8.3.0-1
 From: gcc-defaults/g++@4:8.3.0-1 > gcc-defaults/gcc@4:8.3.0-1 > gcc-8@8.3.0-6 > binutils@2.31.1-16 > binutils/binutils-common@2.31.1-16
 From: gcc-defaults/g++@4:8.3.0-1 > gcc-defaults/gcc@4:8.3.0-1 > gcc-8@8.3.0-6 > binutils@2.31.1-16 > binutils/libbinutils@2.31.1-16 > binutils/binutils-common@2.31.1-16
 From: gcc-defaults/g++@4:8.3.0-1 > gcc-defaults/gcc@4:8.3.0-1 > gcc-8@8.3.0-6 > binutils@2.31.1-16 > binutils/binutils-x86-64-linux-gnu@2.31.1-16 > binutils/binutils-common@2.31.1-16
 and 4 more...

Organization:      docker-desktop-test
Package manager:   deb
Project name:      docker-image|docker-scan
Docker image:      docker-scan:e2e
Platform:          linux/amd64
Licenses:          enabled

Tested 200 dependencies for known issues, found 37 issues.

Linux上安装scan-cli插件

目前Linux系统上的Docker Engine尚未支持scan命令，因此可以通过插件形式使用，可以参考scan-cli-plugin的文档，此处我在Ubuntu上通过apt安装一下

> cat /etc/apt/sources.list.d/docker.list 
deb [arch=amd64] https://mirrors.aliyun.com/docker-ce/linux/ubuntu xenial stable
> apt-get update && apt-get install docker-scan-plugin

安装完成之后，登录Docker hub,然后同意访问Snyk即可。

目录CONTENT

【最佳实践】Docker Scan扫描镜像漏洞

Docker scan本地扫描镜像漏洞

Linux上安装scan-cli插件

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